Solubility of oxygen in aqueous sulphuric acid-metallic salt solutions under pressure leaching conditions.

Abstract

The densities and equilibrium solubilities of oxygen were determined in aqueous sulphuric acid containing different amounts of dissolved zinc and ferric sulphate at conditions that simulated the conditions used for pressure leaching of zinc sulphide ores. A two-stage absorption-desorption process was used in the determination of the oxygen solubilities. The solutions were saturated with oxygen at high temperatures and pressures and then, the volume of gas desorbed at 101.3 kPa and 323 K, was measured. The solubilities of oxygen in these solutions are closely expressed by Henry's law. The oxygen solubilities were found to be very low, in the order of 10$\sp{-5}$ mole fraction at an oxygen partial pressure of 101.3 kPa. The addition of the sulphuric acid and the metal salts was found to significantly decrease the oxygen solubilities. However, the oxygen solubilities increase with an increase in the partial pressure of oxygen and an increase in temperature. At all temperatures, the densities of these solutions were higher than those of water. The densities of the solutions decreased with an increase in temperature. (Abstract shortened by UMI.)